In a conventional tissue forming process, a headbox directs a dilute slurry of papermaking fibers and water (known as the “stock”) onto a moving forming fabric from which it is subsequently transferred downstream as a very wet web onto a though-air dryer (TAD) fabric. The web together with the fabric, pass through a through-air dryer arrangement where the web is molded and dried. In order to create bulk and other desirable tactile properties in this embryonic web, the TAD fabric will ideally impart a surface topography to the eventual sheet which topography can be provided by a combination of recesses, or pockets in the otherwise generally planar PS fabric surface of the fabric, and protrusions, or knuckles, which extend above the fabric plane. The pockets create areas of high fiber concentration in the sheet, while the protrusions form regions of relatively lower fiber concentration; together, the zones of high and low fiber concentration impart desirable softness and absorbency characteristics to the sheet thus formed. Such fabrics are well known and numerous constructions have been described in the prior art. The known fabrics are of either single or multiple layer construction, and are designed to impart a pattern onto the paper sheet which they convey so as to create the aforementioned desirable properties. These known fabrics deliver surface topography using various means, such as by providing a patterned, resin coated surface onto a woven substrate in the manner described for example by Trokhan et al. in U.S. Pat. No. 5,275,700 and others; introducing surface sculpting yarns into the fabric surface as described by Chiu et al. U.S. Pat. No. 5,429,686 or Wendt et al. U.S. Pat. No. 5,627,248; weaving the fabric according to lattice type weave patterns such as described by Hay et al. U.S. Pat. No. 6,237,644; utilizing differing yarn sizes in the PS surface of the fabric as disclosed by Lafond et al. U.S. Pat. No. 7,300,554; other means are known and used.
It is known from Quigley U.S. Pat. No. 7,993,493 (“the '493 patent”) to provide a single layer TAD or forming fabric which is woven according to a 10-shed pattern to provide a plurality of pockets in the paper conveying surface of the fabric. The weave pattern forms pockets on the PS of the fabric, which pockets are defined by:                a) Two sides formed by single warp yarn knuckles each of which passes over at least 3 consecutive weft yarns;        b) The remaining two sides formed by single weft yarn knuckles each of which pass over two consecutive warp yarns;        c) A pattern square including 10 warp and weft yarns, and 10 pockets (each of which may be formed above each warp yarn in the pattern square).        
In other embodiments, the '493 patent also discloses that each warp yarn knuckle may pass over 6 consecutive weft yarns, three of which define one of the 4 sides of a first pocket, the remaining three forming one of the four sides of a second pocket. Each weft yarn knuckle may pass under one of the warp yarn knuckle borders and over the other warp yarn knuckle border. Other variations are described. Fabrics woven according to the '493 patent are of single layer construction (i.e. there is one set of warp yarns which are mutually coplanar), and exhibit longitudinally oriented pockets whose bottoms are formed by a single warp yarn and two weft yarns resulting in the pocket bottom being raised in a T-shape.
While fabrics produced in accordance with the teachings of the '493 patent have met with some success, there still exists a need for a TAD fabric in which pockets having at least two differing sizes are created such that the tissue sheet formed thereon exhibits protrusions of at least two differing sizes and shapes. Such sheets may provide enhanced tactile softness as well as other physical and mechanical properties as would be desirable by the consumer.